The present invention relates to sterile clips used to ligate vessels in mammals and more particularly to sterile clips that are used to close or shut tubular vessels such as blood vessels within the body and to instruments for placing such clips on a vessel to ligate the vessel.
During many surgical procedures the surgeon will have to ligate or close various blood vessels before severing those vessels in order to prevent excessive bleeding during the surgical procedure. There are many types of mechanisms or devices for shutting off the vessel such as ligating clips, hemostatic clips and the like. In some instances the surgeon will tie a ligature or suture about the vessel to close or shut the vessel. Many of the clips are metal and comprise a pair of legs which are connected at one end. The vessel to be ligated is placed between the legs and the legs forced together about the vessel to close the vessel. Clips have also been developed from plastic materials but because plastics don't have the same stress and resiliency characteristics as metals, usually the plastic clips include some type of locking mechanism so that when the legs are urged together about the vessel they are locked in a closed position. Ligating clips are well know in the art and are disclosed in numerous U.S. Pat. Nos. as for example, 3,439,523; 3,270,745; 3,363,628; 3,463,156; 3,439,522; 4,146,130; 4,449,530; 4,424,810; 4,418,694; and 4,638,804.
Ligating clips must ensure closure of the vessel. That is, they should completely shut off blood flow and not allow leakage. Also, the clips must remain closed and should not "pop" open or break because of undue stresses. Such opening or breaking would have disastrous results during surgery. Furthermore, the clips should not slip or slide out of position or off the vessel completely. While it doesn't take much force to collapse and close a vessel, the clips, to ensure closure of that vessel and to ensure that they remain in their closed position, require substantial force to close or change the configuration of the clip so that once closed it will remain in its closed position.
With the advent of endoscopic surgery, it has become very important to substantially reduce the forces to carry out virtually any of the manipulations required in an endoscopic surgical procedure such as ligating a vessel. In endoscopic surgery, while the business end of the instrument is placed within the body through an appropriate cannula or small incision, the manipulation of that business end by the surgeon is accomplished outside the body. As a result, it becomes more difficult to control the business end of the instrument since it is further removed from the actual operation of the instrument and any slight movement in the manipulation of the instrument outside the body is magnified at the business end of the instrument. Therefore, the greater the force required to close a clip the greater the possibility of movement of the business end of the instrument and the greater the possibility that the clip is improperly placed or improperly closed.
The present invention substantially reduces the forces required to ligate a vessel. The present invention also provides a clip that ensures closure of the vessel once the clip is placed on the vessel. Furthermore, the present invention allows for ligating clips to be made from many different types of materials such as metals, plastics and the like.
Though the novel clip and instrument of the present invention is most appropriate for use in endoscopic procedures and will be so described in the following description it should be pointed out that the clip and/or the instrument could also be used in laparoscopic procedures and even standard open type surgical procedures.